La Redonne-Ensuès english summary
At 08:40, on Friday, 18 August 2017, the conductor of the TER 879719 Miramas – Marseille-Saint-Charles via Martigues, while leaving the Metheron tunnel, noticed the two rear red lights of the TER 879715, which was traveling on the same track in front of him.
The conductor of the TER 879719 initiated emergency braking and stopped near kilometer 857,400, around 50 m from the TER 879715. A collision was avoided.
The cause of this incident is a lack of respect by the signalman in the Martigues station of the procedure that includes, in a situation involving a disruption in the block, to ensure that the bock is free of any traffic before authorising a train conductor to use axle counter reset preparation system and to cross a signal presenting the indication “semaphore.”
The failure to respect the procedure led these two trains to be in the same block when the system only counts one. The first train leaving the block put the signal “open lane” (green light), allowing the entrance of a new train at full speed in the already occupied block.
The organisational and human factors leading to this error are :
- a lack of visualization tools for the positioning of trains to obtain the assurance that the trains leave the block and instructions whose terms can lead to confusion and include contradictions ;
- a lack of understanding with regard to the functioning of the axles counter reset preparation device ;
- difficult management of an incident in a configuration of rapidly occurring events, in which the timing of trains with the same number of axles were separated by 30 minutes.
BEA-TT is providing three recommendations and two invitations in the following areas :
- the clarification of instructions and availability of operational tools ;
- the training and continuous control of agent knowledge in situations involving the disruption of installations ;
- the systematic performance of an impact study, during changes in operation methods, according to the common safety method.